paoli



2 Sheets- Sheet 1.

(No Model.)

J. PAOLI. ENGINEERS INSTRUMENT.

Patented May 26, 1891.

(No Model.) 2 Sheets-Sheet 2.

J. PAOLI.

ENGINEBRS INSTRUMENT.

No. 453,160. Patented May 26,1891.

2" i W W @ham/cg.' l Mz/mr: MM MQMQ @www UNITED STATES PATENT OFFICE.

JOHN PAOLI, OF HOBOKEN, NEV JERSEY, ASSIGNOR TO IVILLIAM KEUFFEL A ANDHERMANN ESSER, OF NEIY YORK, N. Y.

ENGINEERS INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 453,160, dated May 26,1891.

Application led September 20, 1890. Serial No. 365 ,611. (No model.)

or of an assistant and are set up and adjusted and again taken up andretransported at short intervals. i My improvement facilitates thetransportation by its lightness and facilitates the rapid and correctsetting up, and contributes to enable the exact and delicateconstruction to vwithstand rough usage., The arms which receive theleveling-screws are split and receive those screws in adjustable holes,which allow the friction to be' made uniform under all conditions ofwear. The arms are peculiarly formed and are joined to the sleeve notopposite to the arms, but intermediate between them. This divides theforce when an arm is ovcrstrained and avoids injuring the central parts.

The accompanying drawings form a part of sider the best means ofcarrying' out in the invention.

Figure 1 is acentral vertical section partly in side elevation. Fig. 1:Lis a corresponding sec- 3 5 tion of aportion on a largerscale. Fig. 2 isan elevation quartering to the view in Fig. l.

Fig. 3 is a horizontal section on the line oc oo in Fig. l. Fig. 4 is ahorizontal sect-ion on the line y y in Fig. l. Figs. 5 and (i representa portion detached. Fig. 5 is a plan View, and Fig. 6 an elevation. Fig.7 is a vertical section of a portion on a larger scale.

Fig. S is a side elevation. Itshows a modification.

Similar letters of reference indicate correspondin g parts in all thefigures where they occur.

The triangular standards B are sufficiently spread at the bottom toafford a reliable support. One side or leg is nearly vertical. The

this specification and represent what I con-` other branch or leg isinclined beyond the ordinary extent and is twisted, as shown.

I is the nicely-finished intermediate sleeve, sometimes known as theouter center. It is fitted around the inner center A and carvries theimportant part 1*, usually known as the horizontal limb, or, morebriefly, the limb which I make as a substantial casting. The graduationsare made on silver or other white material iirmly fixed on its upperface. 6o

Collars I I2 receive each a clamp K. The connection in each of thesecases is of the ordinary general character, the slow-motion screw. M forthe lower clamp taking hold of the leveling-arms, which are fixed, andthe upper clamp taking hold by the bracket A2 on the alidade or thepartsmounted on the inner center. These clamps perform theirordinaryfunctions, the lowermost connecting the limb at will with the fixedfoundation and 7o the uppermost connecting the limb at will with thetelescope, both being equipped With provisions for very delicatelyturning to small extents after the parts are firmly clamped. Theseclamps are peculiarly equipped to avoid lost motion.- Each isconstructed as a single casting, the part K', which is to serve as thebearing-block, being formed integral with the main part of the clamp,but with a space yat its back. It is adapted to be sprung 8o slightlyinward by the pressure of the corresponding clamping-screw L whenrequired.

The leveling-arms P each receive the corresponding leveling-screw Q in athreaded hole. A split p, produced by sawing with a fine saw, allowsthis portion of the arm to spring slightly, and a screw P adjusts theamount of opening of this split. The metal will yield elasticallysufficient to allow the split to open and close, so that the contact of9o the arm P with the corresponding levelingscrew Q may be made justsufficiently frictional for an indefinite period. The levelingarms P areof more than the usual depth and are joined to the sleeve R at thepoints i'. 95 These points are not radially within the several arms, butwithin the spaces between the arms. Each arm is made open, as shown. Theconstruction is light and strong. In case one of the leveling-arms isoverstrained it roo may be permanently set; but the distribution of thepoints of union to the sleeve R avoids any risk of distorting thelatter, and consequently of possibly injuring the delicate centers A andI within.

I provide for the ordinary horizontal movement of theinstrument upon thebottom plate W, employing the usual partially-spherical bearing T,mounted within a hemispherical case S, with the usual liberty to rock asfar as ever shall be required in practice by the rolling ot' the part Twithin the part S and with the usual liberty to adjust in all directionshorizontally by the movement of the part S upon the fixed bottom plateW; but instead ot' mounting the partial sphere T directly on the sleeveR, I attach it by a false sleeve T which is larger than the exterior ofR, so that there is a slight annular space between. The capacity of thefalse sleeve to spring and bendallows the instrument to endure roughusage without injuring the centers-that is to say, a sufficientlyviolent blow may change the position of the spherical bearing to oneside or the other of the proper axial line, the false sleeve T yieldingto allow such distortion,while the true sleeve R will remain unaffected.The false sleeve is connected to the true sleeve by screwthreads and maybe removed for repairs or renewals.

Modifications may be made without depart4 ing from the principle orsacrificing the advantages of the invention. I prefer to cast the mostupright leg in the bent form required and to cast the other and moreinclined leg with about the proper degree of curvature, but withoutbeing twisted. Then, the considerable twist required being forciblyimpressed with the metal cold or nearly cold, the best condition of theparticles is obtained.

The leveling-screws Q may have the ordinary caps or shields. (Notshown.)

Parts of the invention may be used without the whole.

I do not in this patent claim the peculiarities of the standards and ofthe parts carried thereon in the upper part of the instrument, nor thepeculiarities of the compass and other parts at the mid-height. Such aremade the subjects of separate applications for patents, the first filedApril 8, 1890, Serial No. 347,097, and the last led herewith.

I claim as my invention- 1. In a transit or analogous instrument, theleveling-arms P, having each a split p and contracting-screw P', incombination with the bottom plate XV and with the sleeve R and with theparts mounted thereon, substantially as herein specified.

2. In a transit or analogous instrument, the open-work leveling-arms Pand their adjusting-screws Q, in combination with the outer sleeve R andattached thereto at the points r intermediate between the loveling-arms,as herein specified.

In a transit or analogous instrument, the spherical bearing T and thetrue sleeve R, carrying the contained centers I and A and theirattachments, in combination with each other and with the false sleeveT', the latter inclosing the true sleeve with afree space between andfixed thereto above the bearing, arranged to allow concussions andshocks by the yielding of the false sleeve, as herein specified.

In testimony that I claim the invention above set forth I aiiix mysignature in presence of two witnesses.

JOHN PAOLI.

Witnesses:

CHAs. S. BARBER, Il. A. .IoHNsToNE.

